Manufacturers Part Number - Search by or warn if used when entering New item

It is very frustrating that you cannot search by Manufacturers Part Number. It would also be useful to warn if a duplicate part number is going to be used.

We have multiple suppliers for the same vendor product. Therefore often it is important to know if the product is already in the system or which supplier to use. A quick search or even a warning if the number had already been used would make our Items list more manageable.